For any startup it's greatest asset is the time that it's founders are able to dedicate to the venture. Apart from the time that they are able to extend every person has a set of contact sphere and these contact sphere gives him/her access to certain resources. Resources that otherwise would have been difficult to secure (Space, money, people, marketing reach, client connects, etc.). This fact alone makes the need for a co-founder paramount.
Also, the presence of a co-founder(s) implies that the business has that many more hours from the founders. This is akin to having found more investment.
Talent and the determination to succeed are the currency which startups need most.
If you have a set of highly enterprising individuals who know how to tap their networks effectively, it is even possible to get into real estate business with an extremely small investment.
A startup really does not need money as much as it needs talented and enterprising people. The money is like grease in a machine; it makes thing smoother, easier; the absence of it means more friction (read difficulty); but money does not guarantee success, good people do. Get a team of good people together, the money will find you instead of the other way around.